public class Example4_9 {
  public static void main(String args[]) {
  SIM simOne = new SIM(18810851510L);
  MobileTelephone mobile = new MobileTelephone();
  mobile.setSIM(simOne);
  System.out.println("手机号码:"+mobile.lookNumber());
  SIM simTwo = new SIM(15605570507L);
  mobile.setSIM(simTwo);
  System.out.println("手机号码:"+mobile.lookNumber());
}
}

